Nonflammable varnish



- I Hitherto, varnishes were made ofa var- Patented July 12, 1927.

I t m m'n wme. g appue iq i d my 3 iThisinvention relates to varnishes,more particularly to varnishes embodying a sol- I 'vent whichis'nonflammable underord nary I conditions;

, ni sh "base consistin essentially of resins: or A "asphalts compoun edwith oils ors mllarmaterials, I In order to render thezsame f fli dient'fluidity for application to articles conta ning halogenated aromatic andvali- 10 to be' coated, itlwas customary to; dissolve the "same-iii;various solvents generallyctbr- 'gaf1icnature. Said solvents were;nflammable and hence dangerous to use andithe fumes thereof I weredetrimental to the health ofthe workmen. Recently it has l e-- comedesirable to apply varnish solutions to bodies which--. had, beenpreviously heated and to bodies be subsequentlyheate'd or baked toremove the solvent and cause the 9 varnish base to set and adhere to thebody being coated, Such procedure washighly dangerous with prior varnishsolutions on account of the volatility and combustibility of thesolvents used, particularly in the case of baking-varnish a I I In rderto obviate the dangers inherent in a flammable solvent, it has beenproposed to substitute therefor an emulsified solution of the varnishbase in water. Generall this was accomplished by a sultable emu sifyingagent, such as ammonia and a soap, which' caused the particles ofvarnish base to emulsify withthe water vehicle. I Such latter solutionswere comparatively unstable and had but a limited use. The amount ofvarnish base in emulsion was comparatively small and it required specialmethods of application and drying thereof on the body being coated toobtain a coating, 40 of suflicient thickness for ordinary use.Furthermore, such solutions were unstable, especially in warm weather,which -causedseparation of the in edients thereof.

My invention is irected to an improvement in varnish solutions whichobviates,

the disadvantages above set forth, it being among the objects thereof toprovide a varnish solution which shall be simple to prepare, stableundgr all changes of atmospheric conditions, non-flammable and theproportions of which may be readily changed for various applications ofthe varnish.

In practising my invention, provide a 4% FFlC i 'PIE.IWNS'YIJI ANIA, ASSIGhTQB T0 WESTING- COMPANY, A CORPORATION OF PEHNSY L- nonrnammniin'VABIN-ISH.

1922; s r ai n. 572,960,;

" varnish base which may consist of a gum, 65 i I such "as gilsonite,naphtholpitch, petroleum asphalt,stearin pitch or the v like, compoundedwith suitable oily material, such as tung oil, linseed oil, fish oil,castor oil or the like) j'The ingredients of the varnish base may becompounded in any desired manner wellknown in the art. V

I further provide a mixture of solvents phatio hydrocarbons which havebeen especiallytreated to free the same from acid constituents;Specifically, I prefer to util-,

myself to a mixture. containing from l5zto 60% of carbon tetrachlorideand the remain- IIdcIf monochlorbenzol.

" .A 'specific example of a varnish solution made'in accordance withthis invention'is 5 as follows: I provide a varnish base made by meltingtogether about 1100 kilograms of gilsonite, 600 kilograms of linseed oiland a 125 kilograms of castor oil. I then repare 2750 liters of solventconsisting 0 equal 39 parts of carbon tetrachloride and mono-(lihilorbenzol, the mixture/having a density of The'solvent is treatedwith anadsorbent material to remove any traces of hydrochloric'acidwhich may be present in the solvent because of slight decomposition ofthe chlor' compounds therein. This may be accomplished y agitating thesolvent with,- or passing the same through, a bed containing anadsorbent material such as aluminum hy droxide, silica gel, fullersearth, bone black or the like. The varnish base is then dis solved inthe treated solvent, preferably with the aid of heat.

Such a solution has the slight disadvantage that, if a body is coatedtherewith and the solvent is not completely removed by the subsequentdrying or baking operation, a small amount of acid product may developand cause corrosion ofthe material and consequent cracking or peeling ofthe varnish coating In order to reduce or eliminate this effect, Iprovide a restraining agent which acts in such a manner as to absorbutilized,-the essential re uirement being that they be capable of deveoping slightly alkaline substances in the varnish. Among such agents areurea, substituted ureas, anihn and ,dimeth l anilin. Generally lessthan. -1% thereo is suflicient v to accomplish the de- A sired result.

My varnish solution has several'advan- .tages over prior solutions ofthis character in that it is stable, does not .develop prod-- ucts whichmay be injurious to the varnish or-to the body coated therewith, and theproportions of ingredients thereof may solution containing less solvent,thereby re ducing the cost of the varnish. In order to obtain aquick-drying varnish solution, I increase the proportion of carbontetrachloride and I may substitute therefor, either wholly or in part, anon-flammable material having a lower boiling point, such asdichlormethane or the like. I I

.Although I have describedm'y invention setting forth a specific examplethereof, it is to be understood that it is not limited to the detailsset forth and that various changes.

straining agent.

urea. Y

may be made therein within the scope thereof. For instance, I maysubstitute various chlorinated hydrocarbonsof similar nature for thosespecified and othcrmaterials for treatment of the solvent to remove acidmay be used. The restraining agents which I have mentioned'are obviouslynot the only ones which may be used.-

I claim as my invention: 1 .1. A varnish solution comprising a varnishbase, a solvent containing monochlorbenzol and carbon tetrachlorideamount of restrainin agent.

2. A varnish solution comprising a varnish base, a solvent containinmonochlorbenzol and carbon; tetrachloride free from acid constituentsand a small amountof-reand a small 3. A varnish solution comprising gver-- nish base, a solvent containin monech-lorbenzol and carbontetrachlori' e' free from acid constituents and a small amount of 4. Avarnish solution comprising a varnish base, a solventcontaining-*monochlorbenzol and carbon tetrachloridefree from acidconstituentsand less than 1% of urea.

In testimony whereof, I have hereunto subscribed my name this firstdayof July,

7 P. WEBER. t.

